As used herein, the term “physical access control” or just “access control” refers to the practice of restricting access or entrance to a secure area or physical resource to authorized persons. There are a number of access control systems available to restrict access to secure areas and/or resources. Access to some of these secure areas and/or resources may be gained by presenting an access device appropriate to each access control system. For example, access may be restricted to users with a correct, physical key that opens a physical lock. In some buildings, access may be enabled through the use of an access card that a user can swipe at an access control unit that is affixed to a building. However, limited options are available for users to access the building without a physical key or entry card.
Recent developments have permitted users to access locations based on sharing data, like PINs (personal identification numbers). For example, the user may be granted access to the location by receiving a PIN from a source that has knowledge of the correct PIN. The user may type the PIN into a keypad of the access control unit affixed to the building. However, receiving this PIN can compromise access control when the building is located in a densely populated area or the access control unit is located underground in an area without network access. For example, it may be that the user must receive the PIN prior to arriving at the building, because the user is unable to receive network communications that include the PIN. In some examples, the user may be forced to use less secure methods of maintaining the PIN for the particular building prior to arriving at the access control unit for the building, like writing the PIN on a piece of paper, which can lead to unauthorized access.
Thus, improved methods of granting access to a location and maintaining security of the access methods is needed. Embodiments of the invention address these and other problems, individually and collectively.